Malcolm Turnbull is facing pressure from both sides of the same-sex marriage debate, with former prime minister John Howard and Labor criticising his role in the campaign.
Mr Howard weighed in on Thursday, accusing the government of washing its hands of responsibility around a range of issues which he believes will be impacted if the survey has a majority yes vote.
He said the government had not detailed how to deal with parental rights, freedom of speech, and religious freedom in the event of a bill to legalise same-sex marriage.
"If a Yes vote is recorded there will be overwhelming pressure to 'move on', legislate as quickly as possible, and then put the issue behind parliament," Mr Howard said.
"There will be scant opportunity for serious consideration of protections in the areas I have cited."
Mr Howard dismissed suggestions his concerns were red herrings, arguing it was "completely disingenuous" to say there would not be consequences of changing the definition of marriage.
Meanwhile, Labor frontbencher Penny Wong called on Mr Turnbull to do more to shape the tone of the debate.
She said No campaigners had put forward factually incorrect and irrelevant arguments.
"Prime Minister Turnbull should speak out against some of the arguments that are being put into the public arena including by people of his own party," Senator Wong told ABC radio.
The Australian Bureau of Statistics is aiming to get the survey forms out to 16 million voters by September 25, with the first arriving in mailboxes earlier in the week.